It's a personal decision as to whether to meet the safe harbor requirements. I had taxpayers that preferred to pay the penalties for one reason or another. economically, it's what you earn on the taxes not paid vs what's earned on that money after taxes and penalties.
there are other ways to avoid or reduce underpayment of estimated tax penalties
1) 90% of the current year tax.
2) annualized installment method
3) some taxpayers can control their withholding and may under-withhold early in the year and over-withhold later in the year. sometimes this is normal due to year-end bonuses. taxpayers have the choice of reporting withholding as 1/4 each period or the actual amount.
